1. Field of the Invention
The present invention relates to a microfluidic device produced by a layer manufacturing technology and particularly relates to a microfluidic device, which can be produced easily and can give an optimum processing environment to a process such as reaction of subject fluid.
2. Description of the Related Art
In the field of parts manufacture, a layer manufacturing technology has been recently spread rapidly as a method for forming a computer-designed complex three-dimensional object in a short time. In most cases, the layer manufacturing technology has been applied to relatively large parts with a size not smaller than the order of cm. In recent years, this method has been also applied to microstructures formed by high-precision processing, such as micro-gears, micro-optical parts, microfluidic devices, etc.
Microfluidic device is a generic terms of “microreactor”, “lab-on a chip” or “micro total analytical systems (μ-TAS)”. A microfluidic device can be integrated with another microfluidic device having another function such as synthesis, physicochemical treatment, detection to construct a microchemical system. Because the microfluidic devices are excellent in uniformity of reaction solution temperature and good in temperature response, it is possible to shorten reaction time and save the amount of a sample and the amount of a solvent used. Accordingly, because resources and energy required for production of a device can be saved, the microfluidic devices have merits in energy conservation in operation, reduction in the amount of waste, etc. There is expectation that the microfluidic devices will contribute to many industries in the future.
A microreactor provided as a kind of microfluidic device is a device having a micro reaction field smaller by several orders than that of an conventional reactor. In most cases, the microreactor uses a channel having a diameter of from 1 mm to the order of micros as the reaction field. Accordingly, the microreactor is also referred to as “micro channel reactor”. It is conceived that temperature control can be performed accurately on the basis of reduction in heat capacity because the device surface area per unit volume of such a microreactor is large. Researches into the microreactor have been advanced in various countries because the microreactor is a device particularly having an appeal for catalytic reaction sensitive to temperature and having a reaction rate dependent on the contact area (e.g. see US2005/106078 A).
FIG. 17 shows a microreactor described in US 2005/106078 A. This microreactor 100 is a microstructure provided as a laminate of a first pattern layer 110 serving as a top surface, a plurality of second pattern layers 120 each having a reaction portion 123 in which two source fluids L1 and L2 meet (merge into) and react with each other, and a third pattern layer 130 serving as a bottom portion.
The first pattern layer 110 has: first and second inlets 111a and 111b for inletting the two source fluids L1 and L2 in respectively; and an outlet 120 from which a reaction liquid M obtained as a product of reaction of the source fluids L1 and L2 is drained.
Each of the second pattern layers 120 defines: through-holes 121a, 121b and 121d defined so as to correspond to the inlets 111a and 111b and the outlet 112; a junction 122 in which the two source fluids L1 and L2 led in meet with (merge into) each other; and a reaction portion 123 in which the two source fluids L1 and L2 react with each other.
The microreactor 100 is produced in such a manner that the first to third pattern layers 110 to 130 formed from a glass substrate are pressurized and laminated by thermal fusion. When a plurality of pattern layers each having the same structure as the second pattern layer 120 are laminated, a plurality of reactions can be performed by parallel processing.